The three golden rules of user interface design

The following rules are quoted from memory. I had to learn them for my Computingcourse. They were given to us in notes that had been photocopied from elsewhere. I think they're generally considered public domain. If I discover who invented them, I'll attribute them appropriately. I received a message from Theo Mandel, letting me know that he was the author of the rules. Find his website at http://theomandel.com/resources/golden-rules-of-user-interface-design/.